I'm not sure if this is the problem you're having, but, when playing the game, do your text boxes look like this?
If so, you may need to download Locale Emulator from here and open the game in it.
(different from changing your locale/you don't need to extract or redownload all over again), as Japanese text tends to end up garbled if not opened in Locale Emulator, and the password entry form is the only instance of Japanese text being displayed in the game.
Let me know if that doesn't work, and send me a screenshot of your game if possible.
